Building A Dishwasher From Scratch

November 30, 2020 by Lewin Day 49 Comments

[Billy] was no fan of doing the dishes, but also found commercial solutions lacking. The options on the market simply didn’t fit his cookware and flatware. Instead of compromising, he set out to build a dishwasher of his own design.

The build consists of a whole heap of hardware all lumped in a sizeable plastic tub. A washing machine solenoid lets water into the system, and it’s heated by an element in the base of the tub. It’s then pumped through a garden sprinkler head to give the dishes a good all-over spraying. At the end of a wash cycle, the drain pump then dumps the water to let everything dry off. An ESP8266 and a bank of relays are in place to run the show, with the user selecting wash programs via buttons and a small screen.

It may have taken a couple of years to come together, but [Billy’s] dishwasher seems to get the job done. Files are on Github for those interested, however we’d caution against attempting such a build unless you’re familiar working with plumbing and mains electricity. The other benefit of building your own dishwasher is that you’re less likely to have to patch it against widespread exploits – the security is instead up to you. Video after the break.

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Amazon Sidewalk: Should You Be Co-Opted Into A Private Neighbourhood LoRa Network?

November 30, 2020 by Jenny List 61 Comments

WiFi just isn’t very good at going through buildings. It’s fine for the main living areas of an average home, but once we venture towards the periphery of our domains it starts to become less reliable. For connected devices outside the core of a home, this presents a problem, and it’s one Amazon hope to solve with their Sidewalk product.

It’s a low-bandwidth networking system that uses capability already built into some Echo and Ring devices, plus a portion of the owner’s broadband connection to the Internet. The idea is to provide basic connectivity over longer distances to compatible devices even when the WiFi network is not available, but of most interest and concern is that it will also expose itself to devices owned by other people. If your Internet connection goes down, then your Ring devices will still provide a basic version of their functionality via a local low-bandwidth wide-area wireless network provided by the Amazon devices owned by your neighbours. Continue reading “Amazon Sidewalk: Should You Be Co-Opted Into A Private Neighbourhood LoRa Network?” →

MQTT Dashboard Uses SHARP Memory LCD

November 29, 2020 by Jenny List 7 Comments

One of the more interesting display technologies of the moment comes from Sharp, their memory display devices share the low power advantages of an e-ink display with the much faster updates we would expect from an LCD or similar. We’ve not seen much of them in our community due to cost, so it’s good to see one used in an MQTT dashboard project from [Raphael Baron].

The hardware puts the display at the top of a relatively minimalist 3D printed encloseure with the LOLIN32 ESP32 development board behind it, and with a plinth containing a small rotary encoder and three clicky key switches in front. The most interesting part of the project is surprisingly not the display though, because despite being based upon an ESP32 development board he’s written its software with the aim of being as platform- and display-independent as possible. To demonstrate this he’s produced it as a desktop application as well as the standalone hardware. A simple graphical user interface allows the selection of a range of available sources to monitor, with the graphical results on the right.

All code and other assets for the project can be found in a handy GitHub repository, and to put the thing through its paces he’s even provided a video that we’ve placed below the break. User interfaces for MQTT-connected devices can talk as well as listen, for example this MQTT remote control.

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Robot Sink Helps With The Dishes

November 2, 2020 by Lewin Day 16 Comments

The humble kitchen sink has remained relatively unchanged over the last century. While there are now fancier mixing taps and sleeker fittings available, for most of us, there’s a nozzle that squirts water of varying temperature, and a tub in which to soak dishes. Of course, this leaves plenty of room for improvement, as [Jake] found with his robot sink build.

The sink consists of a robotic nozzle, which he refers to as a “continuum manipulator”. In essence, it’s a nozzle that can be steered with a joystick to aim the flow of water throughout the sink. To move the nozzle, motors pull on steel cables attached to 3D printed collars fastened around the hose. Combined with an on/off switch for the water flow, the sink could be a useful assistive technology for those with disabilities, as demonstrated in the project’s demo video.

We could easily imagine such hardware being combined with a simple computer vision system to further automate the cleaning of dishes. The project actually serves as a proof of concept for work [Jake] is doing to explore 3D printing concrete with similar hardware, albeit scaled up to a more industrial level. We’ve featured similar technology before, too — in the form of a DIY tentacle build that’s perfect for Halloween. Video after the break.

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ESP32 Adds New Features To 1990s Home Alarm System

November 2, 2020 by Tom Nardi 16 Comments

Given how fast technology is progressing, some consumer gadgets lend themselves to being replaced every few years. Mobile phones are a particularly good example of a device that you probably won’t want to hold onto for more than 4 years or so, with TVs not far behind them. On the other hand, something like a home alarm system can stay in the fight for decades. As long as it still goes off when somebody tries to pop a window, what more do you need?

Well if you’re like [Brett Laniosh], you might want the ability to arm the system and check its current status from your phone. But instead of getting a whole new system, he decided to upgrade his circa 1993 Gardiner Gardtec 800 alarm with an ESP32. As it so happens, the original panel has an expansion connector which he was able to tap into without making any modifications to the alarm itself. If you’ve got a similar panel, you might even be able to use his source code and circuit schematics to perform your own modification.

Optocouplers link the ESP and alarm panel.

Now we know what you’re thinking. Surely there’s a risk involved when trusting an ESP32 connected to the Internet with the ability to disarm your home alarm system. [Brett] has considered this, and made sure that the web server running on the microcontroller can only be accessed from the local network. If he does want to connect from beyond WiFi range, he does so through a VPN. In other words, his code is never directly exposed to the wilds of the Internet and is always hiding behind some kind of encryption.

The WiFi connection allows [Brett] to arm and disarm the alarm system remotely, check if it’s been triggered, and reset it if necessary, all from his smartphone. But he’s also added in a 433 MHz receiver so he can use simple handheld fobs to arm the system if he doesn’t want to go through the phone. Even if you dropped out the Internet connectivity, this alone is a pretty nice upgrade.

For those not afraid to take the more invasive route, you could potentially reverse engineer and reprogram your old alarm panel. Or you could even so the full DIY route and create your own low-cost alarm system using the ESP32 and off-the-shelf modules.

The Ground Beneath Your Feet: SuperAdobe Construction

October 27, 2020 by Bryan Cockfield 25 Comments

Homes in different parts of the world used to look different from each other out of necessity, built to optimize for the challenges and benefits of local climate. When residential climate control systems became commonplace that changed. Where a home in tropical south Florida once required very different building methods (and materials) compared to a home in the cold mountains of New England, essentially identical construction methods are now used for single-family homes in any climate. The result is inefficient and virtually indistinguishable housing from coast to coast, regardless of climate. As regions throughout the world are facing increasingly dire housing shortages, the race is on to find solutions that are economical and available to us right now.

The mission of CalEarth, one of the non-profits that Hackaday has teamed up with for this year’s Hackaday Prize, is to address that housing shortage by building energy-efficient homes out of materials already available in the areas that they will be built. CalEarth specializes in building adobe, or earth, homes that have a large thermal mass and an inexpensive bill of materials. Not only does this save on heating and cooling costs, but transportation costs for materials can be reduced as well. Some downside to this method of construction are increased labor costs and the necessity of geometric precision of the construction method, both of which are tackled in this two-month design challenge.

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How An Engineer Designs A DIY Energy Recovery Ventilator

October 21, 2020 by Dan Maloney 81 Comments

We have no idea whether [Nick Goodey] is a trained engineer or not. But given the detailed design of this DIY energy recovery ventilator for his home HVAC system, we’re going to go out on a limb and say he probably knows what he’s doing.

For those not in the know, an energy recovery ventilator (ERV) is an increasingly common piece of equipment in modern residential and commercial construction. As buildings have become progressively “tighter” to decrease heating and cooling energy losses to the environment, the air inside them has gotten increasingly stale. ERVs solve the problem by bringing fresh, unconditioned air in from the outside while venting stale but conditioned air to the outside. The two streams pass each other in a heat exchanger so that much of the energy put into the conditioned air is transferred to the incoming unconditioned air.

While ERV systems are readily available commercially, [Nick] decided to roll his own after a few experiments with Coroplast and some extensive calculations convinced him it would be a viable idea. One may scoff at the idea of corrugated plastic for the heat exchanger, but the smooth channels through the material make it a great choice. He built up a block of Coroplast squares with the channels in alternate layers oriented orthogonally, letting stale inside air pass very close to fresh outside air to exchange heat without ever mixing directly. The entire system, including fans, an Arduino for control, sensors galore, and the Hubitat home automation hub, is powered by DC, so no electrician was needed. [Nick] has a ton of detail in his build log, including all the tools and calculators he used to design the system.

Given the expense of ERV systems, we’re surprised we haven’t seen more stories about DIY versions. We have talked about HVAC systems a lot, though — after all, HVAC techs are hackers who make housecalls.